Gastrulation
involves……..
a) cellular arrangements
b) cellular migration
c) cellular death
d) both a and b
Which of the following begins when a groove with raised edges appears on the dorsal surface of the embryonic disc and establishes the longitudinal axis of the embryo?
a) gastrulation
b) morulation
c) fertilization
d) neurolation
Explanation: the groove with raised edges is called primitive streak
Primitive streak appears on the…….. surface of the embryonic disc during gastrulation.
a) ventral
b) lateral
c) dorsal
d) marginal
Explanation: being or located near, on, or toward the upper surface of an animal (as a quadruped) opposite the lower or ventral surface
Which of the following cells of the embryonic disc migrate medially across other cells and enter the primitive streak?
a) trophoblast
b) epiblast
c) hypoblast
d) none of them
Explanation: epiblast cells are the surface cells of the embryo during gastrulation
Which of the following cells are first displaced by the first epiblast cell during entry into the primitive streak?
a) trophoblast cells
b) other epiblast cells
c) hypoblast cells
d) none of them
Explanation: In amniote embryology, the hypoblast, is one of two distinct layers arising from the inner cell mass in the mammalian blastocyst, or from the blastodisc in reptiles and birds. The hypoblast gives rise to the yolk
Hypoblast cells are of which embryonic layer?
a) allotois
b) amnion
c) chorion
d) yolk sac
Explanation: these cells form the most inferior germ layer.
